ERS-1 SATELLITE - ALONG TRACK SCANNING RADIOMETER (ATSR) DATA

W. Emery (University of Colorado, USA)

Announced availability: 1 March 1995

Data Access

Low-resolution, spatially-Averaged Sea Surface Temperature (ASST) Along Track Scanning Radiometer (ATSR) composites are available on-line from the Colorado Center for Astrodynamics Research via anonymous FTP from ftp://ccar.Colorado.EDU/. Data files are located in subdirectory pub/coare/atsr. Data are also available upon request from NOAA's National Oceanographic Data Center (NODC) in Silver Spring, MD (http://www.nodc.noaa.gov).

Beginning June 1996, data will also be archived at NOAA's National Climatic Data Center (NCDC) in Asheville, NC (http://www.ncdc.noaa.gov) and at the National Center for Atmospheric Research (NCAR) in Boulder, CO (http://dss.ucar.edu/pub/toga_coare/).

BACKGROUND

The ATSR is a four-channel, dual-view, self-calibrating infrared radiometer installed onboard the European Space Agency's (ESA) European Remote Sensing Satellite (ERS-1). The instrument's design allows the global measurement of sea surface temperature to an accuracy of +/- 0.3 K. The visible ATSR channel is at a wavelength of 1.6 um; the three thermal bands are at 3.7, 11, and 12 um.

The dual view design of ATSR, resulting from the instrument's conical scanning mechanism, makes it possible to estimate and correct for atmospheric effects. Each scan takes readings from the nadir position and then sweeps round to take measurements from a point about 900 km along the satellite's track. A few minutes after acquiring the forward view, the satellite passes over the same spot and takes readings for the nadir view. As the two views of the same scene are taken through different atmospheric path lengths, it is possible to calculate a correction for the effect of atmospheric absorption.

Data File Information

The composite ASST maps are contained in two directories, nadir and dual. Map sizes are 720 x 360 (2-byte) navigated to half-degree cells. Each image is a monthly composite. The latitude is provided as a cell number, from the South Pole to the North Pole, in the range 0 to 359. Longitude is provided as a cell number, from 180 degrees West to 180 degrees East, ranging from 0 to 719. The nadir directory contains 1992 (13 files) and 1993 (13 files) images of nadir-only, the dual directory contains 1992 (13 files) and 1993 (12 files) images of dual-only ASST.
File names in the directories are yymm.all.nadir/dual.
Data volume is 4.1 MB.

For more information, please contact:

Andrew Wobido
Colorado Center for Astrodynamics Research
Department of Aerospace Engineering
University of Colorado
Campus Box 431
Boulder, CO 80309
USA

email: wobido@frodo.colorado.edu
Phone: (303) 492-8868
FAX: (303) 492-2825

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